unlzma: fixed speedup/shrink by Pascal Bellard (pascal.bellard AT ads-lu.com)

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2009-09-15 23:40:08 +02:00
parent ba98603264
commit f2c184be83
2 changed files with 108 additions and 146 deletions

View File

@ -298,8 +298,8 @@ config FEATURE_LZMA_FAST
default n
depends on UNLZMA
help
This option reduces decompression time by about 33% at the cost of
a 2K bigger binary.
This option reduces decompression time by about 25% at the cost of
a 1K bigger binary.
config UNZIP
bool "unzip"

View File

@ -8,14 +8,15 @@
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
#include "unarchive.h"
#if ENABLE_FEATURE_LZMA_FAST
# define speed_inline ALWAYS_INLINE
# define size_inline
#else
# define speed_inline
# define size_inline ALWAYS_INLINE
#endif
@ -44,36 +45,48 @@ typedef struct {
#define RC_MODEL_TOTAL_BITS 11
/* Called twice: once at startup and once in rc_normalize() */
static void rc_read(rc_t *rc)
/* Called twice: once at startup (LZMA_FAST only) and once in rc_normalize() */
static size_inline void rc_read(rc_t *rc)
{
int buffer_size = safe_read(rc->fd, RC_BUFFER, RC_BUFFER_SIZE);
//TODO: return -1 instead
//This will make unlzma delete broken unpacked file on unpack errors
if (buffer_size <= 0)
bb_error_msg_and_die("unexpected EOF");
rc->ptr = RC_BUFFER;
rc->buffer_end = RC_BUFFER + buffer_size;
}
/* Called twice, but one callsite is in speed_inline'd rc_is_bit_1() */
static void rc_do_normalize(rc_t *rc)
{
if (rc->ptr >= rc->buffer_end)
rc_read(rc);
rc->range <<= 8;
rc->code = (rc->code << 8) | *rc->ptr++;
}
/* Called once */
static rc_t* rc_init(int fd) /*, int buffer_size) */
static ALWAYS_INLINE rc_t* rc_init(int fd) /*, int buffer_size) */
{
int i;
rc_t *rc;
rc = xmalloc(sizeof(*rc) + RC_BUFFER_SIZE);
rc = xzalloc(sizeof(*rc) + RC_BUFFER_SIZE);
rc->fd = fd;
/* rc->buffer_size = buffer_size; */
rc->buffer_end = RC_BUFFER + RC_BUFFER_SIZE;
rc->ptr = rc->buffer_end;
/* rc->ptr = rc->buffer_end; */
rc->code = 0;
rc->range = 0xFFFFFFFF;
for (i = 0; i < 5; i++) {
#if ENABLE_FEATURE_LZMA_FAST
if (rc->ptr >= rc->buffer_end)
rc_read(rc);
rc->code = (rc->code << 8) | *rc->ptr++;
#else
rc_do_normalize(rc);
#endif
}
rc->range = 0xFFFFFFFF;
return rc;
}
@ -83,14 +96,6 @@ static ALWAYS_INLINE void rc_free(rc_t *rc)
free(rc);
}
/* Called twice, but one callsite is in speed_inline'd rc_is_bit_0_helper() */
static void rc_do_normalize(rc_t *rc)
{
if (rc->ptr >= rc->buffer_end)
rc_read(rc);
rc->range <<= 8;
rc->code = (rc->code << 8) | *rc->ptr++;
}
static ALWAYS_INLINE void rc_normalize(rc_t *rc)
{
if (rc->range < (1 << RC_TOP_BITS)) {
@ -98,49 +103,28 @@ static ALWAYS_INLINE void rc_normalize(rc_t *rc)
}
}
/* rc_is_bit_0 is called 9 times */
/* Why rc_is_bit_0_helper exists?
* Because we want to always expose (rc->code < rc->bound) to optimizer.
* Thus rc_is_bit_0 is always inlined, and rc_is_bit_0_helper is inlined
* only if we compile for speed.
*/
static speed_inline uint32_t rc_is_bit_0_helper(rc_t *rc, uint16_t *p)
/* rc_is_bit_1 is called 9 times */
static speed_inline int rc_is_bit_1(rc_t *rc, uint16_t *p)
{
rc_normalize(rc);
rc->bound = *p * (rc->range >> RC_MODEL_TOTAL_BITS);
return rc->bound;
}
static ALWAYS_INLINE int rc_is_bit_0(rc_t *rc, uint16_t *p)
{
uint32_t t = rc_is_bit_0_helper(rc, p);
return rc->code < t;
}
/* Called ~10 times, but very small, thus inlined */
static speed_inline void rc_update_bit_0(rc_t *rc, uint16_t *p)
{
rc->range = rc->bound;
*p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS;
}
static speed_inline void rc_update_bit_1(rc_t *rc, uint16_t *p)
{
if (rc->code < rc->bound) {
rc->range = rc->bound;
*p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS;
return 0;
}
rc->range -= rc->bound;
rc->code -= rc->bound;
*p -= *p >> RC_MOVE_BITS;
return 1;
}
/* Called 4 times in unlzma loop */
static int rc_get_bit(rc_t *rc, uint16_t *p, int *symbol)
static speed_inline int rc_get_bit(rc_t *rc, uint16_t *p, int *symbol)
{
if (rc_is_bit_0(rc, p)) {
rc_update_bit_0(rc, p);
*symbol *= 2;
return 0;
} else {
rc_update_bit_1(rc, p);
*symbol = *symbol * 2 + 1;
return 1;
}
int ret = rc_is_bit_1(rc, p);
*symbol = *symbol * 2 + ret;
return ret;
}
/* Called once */
@ -236,14 +220,11 @@ unpack_lzma_stream(int src_fd, int dst_fd)
int lc, pb, lp;
uint32_t pos_state_mask;
uint32_t literal_pos_mask;
uint32_t pos;
uint16_t *p;
uint16_t *prob;
uint16_t *prob_lit;
int num_bits;
int num_probs;
rc_t *rc;
int i, mi;
int i;
uint8_t *buffer;
uint8_t previous_byte = 0;
size_t buffer_pos = 0, global_pos = 0;
@ -251,14 +232,17 @@ unpack_lzma_stream(int src_fd, int dst_fd)
int state = 0;
uint32_t rep0 = 1, rep1 = 1, rep2 = 1, rep3 = 1;
xread(src_fd, &header, sizeof(header));
if (full_read(src_fd, &header, sizeof(header)) != sizeof(header)
|| header.pos >= (9 * 5 * 5)
) {
bb_error_msg("bad lzma header");
return -1;
}
if (header.pos >= (9 * 5 * 5))
bb_error_msg_and_die("bad header");
mi = header.pos / 9;
i = header.pos / 9;
lc = header.pos % 9;
pb = mi / 5;
lp = mi % 5;
pb = i / 5;
lp = i % 5;
pos_state_mask = (1 << pb) - 1;
literal_pos_mask = (1 << lp) - 1;
@ -266,13 +250,13 @@ unpack_lzma_stream(int src_fd, int dst_fd)
header.dst_size = SWAP_LE64(header.dst_size);
if (header.dict_size == 0)
header.dict_size = 1;
header.dict_size++;
buffer = xmalloc(MIN(header.dst_size, header.dict_size));
num_probs = LZMA_BASE_SIZE + (LZMA_LIT_SIZE << (lc + lp));
p = xmalloc(num_probs * sizeof(*p));
num_probs = LZMA_LITERAL + (LZMA_LIT_SIZE << (lc + lp));
num_probs += LZMA_LITERAL - LZMA_BASE_SIZE;
for (i = 0; i < num_probs; i++)
p[i] = (1 << RC_MODEL_TOTAL_BITS) >> 1;
@ -280,11 +264,13 @@ unpack_lzma_stream(int src_fd, int dst_fd)
while (global_pos + buffer_pos < header.dst_size) {
int pos_state = (buffer_pos + global_pos) & pos_state_mask;
uint16_t *prob = p + LZMA_IS_MATCH + (state << LZMA_NUM_POS_BITS_MAX) + pos_state;
if (!rc_is_bit_1(rc, prob)) {
static const char next_state[LZMA_NUM_STATES] =
{ 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 4, 5 };
int mi = 1;
prob = p + LZMA_IS_MATCH + (state << LZMA_NUM_POS_BITS_MAX) + pos_state;
if (rc_is_bit_0(rc, prob)) {
mi = 1;
rc_update_bit_0(rc, prob);
prob = (p + LZMA_LITERAL
+ (LZMA_LIT_SIZE * ((((buffer_pos + global_pos) & literal_pos_mask) << lc)
+ (previous_byte >> (8 - lc))
@ -294,8 +280,8 @@ unpack_lzma_stream(int src_fd, int dst_fd)
if (state >= LZMA_NUM_LIT_STATES) {
int match_byte;
uint32_t pos = buffer_pos - rep0;
pos = buffer_pos - rep0;
while (pos >= header.dict_size)
pos += header.dict_size;
match_byte = buffer[pos];
@ -304,22 +290,16 @@ unpack_lzma_stream(int src_fd, int dst_fd)
match_byte <<= 1;
bit = match_byte & 0x100;
prob_lit = prob + 0x100 + bit + mi;
bit ^= (rc_get_bit(rc, prob_lit, &mi) << 8); /* 0x100 or 0 */
bit ^= (rc_get_bit(rc, prob + 0x100 + bit + mi, &mi) << 8); /* 0x100 or 0 */
if (bit)
break;
} while (mi < 0x100);
}
while (mi < 0x100) {
prob_lit = prob + mi;
rc_get_bit(rc, prob_lit, &mi);
rc_get_bit(rc, prob + mi, &mi);
}
state -= 3;
if (state < 4-3)
state = 0;
if (state >= 10-3)
state -= 6-3;
state = next_state[state];
previous_byte = (uint8_t) mi;
#if ENABLE_FEATURE_LZMA_FAST
@ -338,59 +318,46 @@ unpack_lzma_stream(int src_fd, int dst_fd)
#endif
} else {
int offset;
uint16_t *prob_len;
uint16_t *prob2;
#define prob_len prob2
rc_update_bit_1(rc, prob);
prob = p + LZMA_IS_REP + state;
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
prob2 = p + LZMA_IS_REP + state;
if (!rc_is_bit_1(rc, prob2)) {
rep3 = rep2;
rep2 = rep1;
rep1 = rep0;
state = state < LZMA_NUM_LIT_STATES ? 0 : 3;
prob = p + LZMA_LEN_CODER;
prob2 = p + LZMA_LEN_CODER;
} else {
rc_update_bit_1(rc, prob);
prob = p + LZMA_IS_REP_G0 + state;
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
prob = (p + LZMA_IS_REP_0_LONG
prob2 += LZMA_IS_REP_G0 - LZMA_IS_REP;
if (!rc_is_bit_1(rc, prob2)) {
prob2 = (p + LZMA_IS_REP_0_LONG
+ (state << LZMA_NUM_POS_BITS_MAX)
+ pos_state
);
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
state = state < LZMA_NUM_LIT_STATES ? 9 : 11;
if (!rc_is_bit_1(rc, prob2)) {
#if ENABLE_FEATURE_LZMA_FAST
pos = buffer_pos - rep0;
uint32_t pos = buffer_pos - rep0;
state = state < LZMA_NUM_LIT_STATES ? 9 : 11;
while (pos >= header.dict_size)
pos += header.dict_size;
previous_byte = buffer[pos];
goto one_byte1;
#else
state = state < LZMA_NUM_LIT_STATES ? 9 : 11;
len = 1;
goto string;
#endif
} else {
rc_update_bit_1(rc, prob);
}
} else {
uint32_t distance;
rc_update_bit_1(rc, prob);
prob = p + LZMA_IS_REP_G1 + state;
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
distance = rep1;
} else {
rc_update_bit_1(rc, prob);
prob = p + LZMA_IS_REP_G2 + state;
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
distance = rep2;
} else {
rc_update_bit_1(rc, prob);
prob2 += LZMA_IS_REP_G1 - LZMA_IS_REP_G0;
distance = rep1;
if (rc_is_bit_1(rc, prob2)) {
prob2 += LZMA_IS_REP_G2 - LZMA_IS_REP_G1;
distance = rep2;
if (rc_is_bit_1(rc, prob2)) {
distance = rep3;
rep3 = rep2;
}
@ -400,31 +367,27 @@ unpack_lzma_stream(int src_fd, int dst_fd)
rep0 = distance;
}
state = state < LZMA_NUM_LIT_STATES ? 8 : 11;
prob = p + LZMA_REP_LEN_CODER;
prob2 = p + LZMA_REP_LEN_CODER;
}
prob_len = prob + LZMA_LEN_CHOICE;
if (rc_is_bit_0(rc, prob_len)) {
rc_update_bit_0(rc, prob_len);
prob_len = (prob + LZMA_LEN_LOW
+ (pos_state << LZMA_LEN_NUM_LOW_BITS));
prob_len = prob2 + LZMA_LEN_CHOICE;
num_bits = LZMA_LEN_NUM_LOW_BITS;
if (!rc_is_bit_1(rc, prob_len)) {
prob_len += LZMA_LEN_LOW - LZMA_LEN_CHOICE
+ (pos_state << LZMA_LEN_NUM_LOW_BITS);
offset = 0;
num_bits = LZMA_LEN_NUM_LOW_BITS;
} else {
rc_update_bit_1(rc, prob_len);
prob_len = prob + LZMA_LEN_CHOICE_2;
if (rc_is_bit_0(rc, prob_len)) {
rc_update_bit_0(rc, prob_len);
prob_len = (prob + LZMA_LEN_MID
+ (pos_state << LZMA_LEN_NUM_MID_BITS));
prob_len += LZMA_LEN_CHOICE_2 - LZMA_LEN_CHOICE;
if (!rc_is_bit_1(rc, prob_len)) {
prob_len += LZMA_LEN_MID - LZMA_LEN_CHOICE_2
+ (pos_state << LZMA_LEN_NUM_MID_BITS);
offset = 1 << LZMA_LEN_NUM_LOW_BITS;
num_bits = LZMA_LEN_NUM_MID_BITS;
num_bits += LZMA_LEN_NUM_MID_BITS - LZMA_LEN_NUM_LOW_BITS;
} else {
rc_update_bit_1(rc, prob_len);
prob_len = prob + LZMA_LEN_HIGH;
prob_len += LZMA_LEN_HIGH - LZMA_LEN_CHOICE_2;
offset = ((1 << LZMA_LEN_NUM_LOW_BITS)
+ (1 << LZMA_LEN_NUM_MID_BITS));
num_bits = LZMA_LEN_NUM_HIGH_BITS;
num_bits += LZMA_LEN_NUM_HIGH_BITS - LZMA_LEN_NUM_LOW_BITS;
}
}
rc_bit_tree_decode(rc, prob_len, num_bits, &len);
@ -432,37 +395,36 @@ unpack_lzma_stream(int src_fd, int dst_fd)
if (state < 4) {
int pos_slot;
uint16_t *prob3;
state += LZMA_NUM_LIT_STATES;
prob = p + LZMA_POS_SLOT +
prob3 = p + LZMA_POS_SLOT +
((len < LZMA_NUM_LEN_TO_POS_STATES ? len :
LZMA_NUM_LEN_TO_POS_STATES - 1)
<< LZMA_NUM_POS_SLOT_BITS);
rc_bit_tree_decode(rc, prob, LZMA_NUM_POS_SLOT_BITS,
&pos_slot);
rc_bit_tree_decode(rc, prob3,
LZMA_NUM_POS_SLOT_BITS, &pos_slot);
rep0 = pos_slot;
if (pos_slot >= LZMA_START_POS_MODEL_INDEX) {
num_bits = (pos_slot >> 1) - 1;
int i2, mi2, num_bits2 = (pos_slot >> 1) - 1;
rep0 = 2 | (pos_slot & 1);
if (pos_slot < LZMA_END_POS_MODEL_INDEX) {
rep0 <<= num_bits;
prob = p + LZMA_SPEC_POS + rep0 - pos_slot - 1;
rep0 <<= num_bits2;
prob3 = p + LZMA_SPEC_POS + rep0 - pos_slot - 1;
} else {
num_bits -= LZMA_NUM_ALIGN_BITS;
while (num_bits--)
for (; num_bits2 != LZMA_NUM_ALIGN_BITS; num_bits2--)
rep0 = (rep0 << 1) | rc_direct_bit(rc);
prob = p + LZMA_ALIGN;
rep0 <<= LZMA_NUM_ALIGN_BITS;
num_bits = LZMA_NUM_ALIGN_BITS;
prob3 = p + LZMA_ALIGN;
}
i = 1;
mi = 1;
while (num_bits--) {
if (rc_get_bit(rc, prob + mi, &mi))
rep0 |= i;
i <<= 1;
i2 = 1;
mi2 = 1;
while (num_bits2--) {
if (rc_get_bit(rc, prob3 + mi2, &mi2))
rep0 |= i2;
i2 <<= 1;
}
} else
rep0 = pos_slot;
}
if (++rep0 == 0)
break;
}
@ -470,7 +432,7 @@ unpack_lzma_stream(int src_fd, int dst_fd)
len += LZMA_MATCH_MIN_LEN;
IF_NOT_FEATURE_LZMA_FAST(string:)
do {
pos = buffer_pos - rep0;
uint32_t pos = buffer_pos - rep0;
while (pos >= header.dict_size)
pos += header.dict_size;
previous_byte = buffer[pos];